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Intensified turbulent mixing in the boundary current system of southern Greenland
Author(s) -
Lauderdale Jonathan M.,
Bacon Sheldon,
Naveira Garabato Alberto C.,
Holliday N. Penny
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl032785
Subject(s) - oceanography , boundary current , geology , entrainment (biomusicology) , sill , thermohaline circulation , groenlandia , current (fluid) , north atlantic deep water , water mass , mixing (physics) , water column , bay , ocean current , gulf stream , north atlantic oscillation , climatology , physics , geochemistry , philosophy , ice sheet , quantum mechanics , rhythm , aesthetics
The southern Greenland Deep Western Boundary Current (DWBC) advects major components of North Atlantic Deep Water. Turbulent diapycnal mixing rates of ∼10 −4 m 2 s −1 commonly occur in the DWBC. These diffusivities, estimated with an internal wave strain‐based parameterisation, are independently confirmed by budgets of density and dissolved O 2 . “Moderate” mixing rates (∼10 −4 m 2 s −1 ) over the DWBC path between Denmark Strait and Cape Farewell (∼1000 km) drive a similar net increase in volume transport by diapycnal entrainment to the more intense (∼10 −3 m 2 s −1 ), localised mixing rates found near the Denmark Strait overflow sill. Therefore turbulent mixing associated with the DWBC south of Denmark Strait is instrumental in establishing the magnitude of the North Atlantic Meridional Overturning Circulation. Elevated mixing rates are also seen in the East and West Greenland Currents; this may be significant in preconditioning seasonal restratification of the intermediate layers of the Irminger and Labrador basins.